A 400ms pause on every request, once an hour, caused by a cache cleanup nobody thought of as expensive. Redis is single-threaded, and freeing memory is work.
Reads moved to a replica and checkout started showing empty carts. Read-after-write, sticky connections, and measuring the lag rather than assuming it.
With depends_on conditions gone, a healthcheck is how one service learns another is usable — and it is more honest, because it tests the thing rather than the…
Every project has eight levels available and uses three, inconsistently, so error means “something a developer should look at” in one service and “a customer typed the wrong…
Centralised logs from four services are four streams in one place until something ties a single request together across them. That something has to be generated at the…